coffin



UNITED STATES PATENT OFFICE.

ISAAC N. COFFIN, OF WASHINGTON, DISTRICT OF COLUMBIA.

LARD-LAMP.

Specification forming part of Letters Patent No. 16,825, dated March 17,1857; Reissued March 16, 1858, No. 537.

To all whom it may concern Be it known that I, Isaac N. CorrIN, ofWashington, in the District of Columbia, have invented a new and usefulImprovement in Lard-Lamps; and I do hereby declare that the following isa full, clear, and exact description of the construction and operationof the same.

The nature of my invention consists in an improvement in lard lampsconstituted by the combination of two flat inclined wick tubes with aconcave reflector formed on the top of the lamp reservoir, whichreflector by throwing the heat back on the inner sides of the tubes, onthe wicks, on the air which ascends between the wick tubes, on the lardon the wicks, on the vapor of the lard, and on the flame, and also byheating the air by reflecting heat on the tubes against which the airimpinges in its ascent between them and rubs in its attempts to risevertically, increases the heat in all of these and thereby efl'ectuallyvolatilizes lard, a very viscid substance and very diflicult tovolatilize, to the high degree necessary to form pure flame purifiedfrom smoke, burns the smoke, in creases the size and of course radiatingsurface of the flame, and gives more light, and by the additional heatthus thrown enables my lamp to omit all the usual devices in lard lampscalled heaters and omit all the usual devices in lard lamps for raisinglard up to the wick, where it can be melted or kept melted, such aspistons, screws, &c.

To enable others skilled in the art to make and use my invention I willproceed to describe its construction and operation.

I construct for the cap of my lamp a concave reflector, attaching thelower side to the ordinary screw of the lamp cap. This concave reflectorI combine with two flat wick tubes, by placing the flat wick tubesthrough the concave reflector at right angles to each other at such adistance apart from each other that when inclined toward each other andfixed in position their upper ends are three siX-teenths of an inchapart.

Figure 1, in the accompanying drawings, exhibits the structure of thisimprovement and combination of the two flat inclined wick tubes with theconcave reflector, in which a, a, are the two flat wick tubes inclinedtoward each other at right angles; 71, the concave reflector; m, thespace between the upper ends of the wick tubes; 0, 0, under sides of thetubes (1, a, between their upper ends and the concave reflector. Fig. 2,exhibits a perspective View of one of the wick tubes detached.

The wick tubes are loose in the concave reflector and can be readilywithdrawn from the lamp for filling, cleaning, &c. The wick tubes areprovided with small projections or lugs e, e, by which they are checkedand held in place, the lugs resting on the concave reflector. The wicktubes have a slit from top to bottom (6) and an opening (0 the morefreely to admit the lard to the wick. In order to preserve theinclination and position of the wick tubes they are supported by stripsor wings of metal 6 6 attached firmly to the under side of the cap andinclined to each other at the same angle with the tubes, viz. a rightangle. The' little projections 6 e*, on the edges of the wick tubes aidin preventing the wick tubes from being drawn upward when picking up thewick. It will be seen that from the position of the concave reflectorrelatively to the tubes that the heat radiated from the flame on theconcave reflector will be reflected back on the under sides 0, 0, of theflat inclined wick tubes, that the heat will be reflected on the wicks,on the lard which boils up in foam on the wicks, on the air whichascends between the wick tubes, on the vapor of the lard, and on theflame. By this combination of the concave reflector and the two inclinedflat wick tubes as above described the atmospheric air which entersbetween the two wick tubes above the concave reflector, whose tendencyafter entering is to ascend in a perpendicular direction, is pressed (bythe pressure of the atmosphere at the two sides) against the hot innersides of the tubes in its attempts to rise vertically, at the pressureof at least 1% pounds on the square inch. By this pressure and abrasionof the air against the hot inner sides of the two tubes it is constantlyacquiring in the minutest steps of its ascension greater and greaterheat by pressing against hotter and hotter portions of both of thetubes, till at last it is wire-drawn between the hot sides of the upperends of the two tubes, and through both flames, receiving a fire fromboth sides of the battery of flame, and at same time from the concavereflector battery below, and the volume of air and vapor being thin theheat thrown from each side combined with that which is reflected frombelow pervades every particle and molecule of it, raising it to a veryintense heat. By the action of this concave reflector in imparting heatto the air in its ascent it brings the powerful aid to the heat of theflame of this intensely heated air to conjointly with the hot upper endsof the two tubes, and their flames, act on the vapor of the lard andcauses the combustion to become very thorough and the minutest particleof carbon in the vapor is reduced to its constituent mole cules .in theform of gas. Also a supply of hot oxygen (that which forms a portion ofthe atmospheric air) is aflorded to it, which enters into the mostintimate possible combination with the carbureted hydrogen. From theseactions a very intense combustion and heat is produced, which heatreacts on the wicktubes, (inclusive of the combined action of theconcave reflector in throwing heat on them,) which convey suflicientheat to the lard in the reservoir of the lamp to continue the fusion ofthe lard. Lard being a very viscid substance requires a strong heat andheated air to burn it without smoke, and both of these by thecombination of the concave reflector with the two inclined flat wicktubes, all above described, I am enabled to give it, thereby reducingall the vapor and all the smoke to combustible gas. By this combinationof the concave reflector with the two flat inclined wicktubes I amenabled in the construction of my lard lamp entirely to omit a heatingwire or strip of metal called a heater, so common in lard lamps, theobjections to which are, that it materially obstructs the supply of air,and the shadow cast by it, and its refrigerating effect upon the flame,render lard lamps useless, and also am enabled entirely to omit alldevices, such as pistons, screws, &c., for raising the lard tothe wick,the objections to which are that the complica tions of such contrivancesand their liability to get out of order render lard lamps too expensive.I am enabled by this combination to burn lard in cold weather withsuccess.

To operate or use this lamp, I melt a little lard in a cup or otherconvenient vessel by setting it on the fire or holding it over the flameof a lamp and pour it .in on that which is cold and at the same time setthe lamp down by the fire for a short time to fuse that which is on thewick and in the tubes.

I hereby disclaim the arrangement of flat inclined wick tubes at rightangles to each other that having been done by H. W'. Revely, but claimThe combination of the flat inclined wick tubes at right angles to eachother with the concave reflector as above described for the purposesabove mentioned.

ISAAC N. COFFIN.

Witnesses:

Z. K. OFFUT, T. C. DONN.

[FIRST PRINTED 1912.]

